Reactivating Facebook means your friends will reappear in your friends list again and any new status updates you write will start showing up in your friends' news feeds and your friends will be able to tag you in their posts.

The below reactivation instruction is only valid if your account was deactivated, not if your account was permanently deleted from Facebook. If you're not sure what you've done, either go ahead and follow these steps to see if you can get back in or understand the difference between deactivating and deleting a Facebook account

How to Reactivate Facebook

Sign in to Facebook at Facebook.com, logging in with the two boxes at the very top right of the screen. Use the same email and password you used when you last signed into Facebook.
​That's it! Now, while that is really simple, it's possible you don't even remember your Facebook password. In that case, you reset it:

Just below the login fields is a link called Forgot account?. Click that and then type the email address or phone number you have associated with your account. You might need to answer some other identifiable information before Facebook will let you in.